B-2 Spirit stealth bomber of the USAF. Stealth aircraft are designed to avoid detection using a variety of advanced technologies that reduce reflection/emission of radar, infrared, visible light, radio-frequency (RF) spectrum, and audio, collectively known as stealth technology. Development of stealth technology likely began in Germany during World War II. Well-known modern examples of stealth aircraft include the F-117 Nighthawk, the B-2 Spirit, the F-22 Raptor,and the F-35 Lightning II.
1942 WWII Warplane Identification Chart, German and British Air Force